The pathologist and the hospital clinical laboratory.

In this article, the author conceptualizes problems in pathology through the perspective of a wide angle lens. He explores how the role of the clinical pathologist evolved into what it is now as well as what, in his view, it ideally should be. The author encourages his peers to analyze, critique, and comment on the opinion he sets forth in the following pages.

Neuroendocrinoma of the jejunum: electron microscopic and biochemical analysis.

A 56-year-old woman presented with a sudden, severe hemorrhage per rectum. Angiography localized a jejunal tumor, which was excised. Light microscopy suggested a neuroendocrine tumor, but neither a smooth muscle tumor nor a lymphoma could be excluded. Electron microscopy showed dense cored, single membrane bound secretory granules 150--220 nm in diameter; myofilaments were not observed. Biochemical analysis of tumor tissue yielded considerable amounts of catecholamines. VMA, 5-HIAA, and metanephrines. These combined ultrastructural and biochemical observations establish the diagnosis of neuroendocrine tumor; however, in this case neither type of information is sufficiently specific to define the tumor as either a paraganglioma or a carcinoid. Although paraganglia and mucosal endocrine cells in the GI are currently thought to constitute distinct cell types, they share numerous structural and functional properties, and they are both thought to be part of the APUD cell system. These parallels and similarities are shared by the neoplasms derived from them which often display features of both. In the absence of specific granule types or specific substances isolated from tumor tissue, only the application of specific immunocytochemistry techniques may allow the precise "functional" classification of such tumors.

Dyssegmental dwarfism. A lethal anisospondylic camptomicromelic dwarfism.

Dyssegment dwarfism is a lethal anisospondylic camptomicromelic form of growth retardation that appears to have autosomal recessive inheritance. It is characterized by short neck, cleft palate, narrow chest, severe shortening of long bones and trunk, reduced joint mobility, inguinal hernia, and probably hirsutism and hydroureter/hydronephrosis. Some cases are seen with occipital exencephalocele. The long bones are short and bent with metaphyseal flaring. The vertebral bodies are of different size and many consist of separate ossified masses. The iliac bones are small with hypoplasia of the horizontal and inferior margina. Maturation of cartilage cells at the epiphyseal plates is grossly disturbed and there are puddle-like spaces among the resting cartilage cells.